tunning disk cache for pgsql?

[Nicolas Haller]

Hi all,

I use a new box with 4GB RAM as a pgsql server. In pgsql, you can
set the effective_cache_size to indicate the memory available to cache
disk I/O.
As "recommended", my box use 1300MB to shared buffers (IPC shared memory)
and 2700 Mo to disk cache.

If I look memory usage in top, it say:
Mem: 1154M Active, 1911M Inact, 601M Wired, 112M Cache, 417M Buf, 148M Free

So I think FreeBSD must be limited using memory to cache I/O disk by
some sysctl variables but I don't know which ones. I'm a little bit
confused with some posts I found in this ML :-/

If someone can help me, it will be great.

Regards,

-- 
Nicolas Haller